Pickling vat and coating therefor



Aug. l, 1933. w.; sMi-rh 1,920,486

PICKLING VAT AND COATING THEREFOR Filed'Nov.- 29. 1929 lNvENToR BY M /qAfm /A ATTORNEY Patented ug'. 1, 1933 PATEN'il OFFICE PICKLING VA'll`AND COATING THEREFOR William E. Smith, Lakewood, Ohio ApplicationNovember 29, 1929. Serial No. 410,424

5 Claims.

My invention is an improvement in protective coating compositions and inthe method of applying the same.

In pickling steel or other metals it is the common practice to place theparts in a vat or tank containing a bath of suitable material, such assulphuric, muriatic and nitric acids, ammonia, oil, etc. Such tubs orvats areusually formed of wood, steel or concrete, and heretofore greatdifficultyA has been experienced in protecting the materials of the vatagainst charring, corrosion,

, or other destructive reactions. Lam aware that faces of the vatmaterial are protected from conattempts have been made heretofore toprotect the vats by coating the same with certain materials, but as faras I am aware, such attempts have not been successful to the extent ofcompletely protecting the inner surfaces of the vat material.Furthermore, I have found that the coating compositions are exposed tocontact with the pickling bath, resulting in chemical reaction betweenthe coating and bath, and deterioration of the coating.

It is one of the objects of my invention, therefore, to overcome andeliminate the disadvantages and diinculties heretofore encountered, byapplying a protective coating to a vat or other container in such amanner that the inner surtact with `the pickling bath.

Another object of my invention is to prevent injury to the protectivecomposition or coating, due to contact with the pickling solution orwith objects placed in the vat.

A further object of my invention is to enable leaky tanks or vats to berepaired by applying my protective composition in a plastic state, as,for instance, in wooden tanks lined with lead which have becomepunctured or damaged.

Another object of the invention is to provide a composition of matterresistant-to corrosion and active chemical reaction with a picklingbath, and which is capable of being applied to a surface in a plasticstate, the exposed surface of the composition forming a protective andmaterial supporting crust.

Other objects and advantages of my invention will become more apparentfrom the following description of an embodiment thereof, reference beingmade to the accompanying drawing in which like reference characters areemployed to tion.

Fig. 2 is a broken section of a Wooden tank or vat illustrating themethod of applying the protective coating.

By the use of my invention, tanks or vats of Wood, concrete or steel maybe effectively protected from corrosion, injury and leakage, due to thechemical action of the pickling fluids contained in such vats or tanks.By the use of my invention the useful life of old containers may beincreased indefinitely, by patching punctured portions of the usual leadlining with a material made in accordance with my invention. The leadlining of old vats may also be entirely removed and a coating of mycomposition applied in accordance with my invention.

I prefer to employ a composition of matter which is resistant to acidsand alkalis used in pickling and plating baths, and which may be appliedby means of a trowel or brush to form a smooth homogeneous coating orlining. I also prefer to employ such a composition which will dryquickly to touch and which will form an outer supporting crust.

I have discovered that the following composition of matter givesexcellent results and possesses the above mentioned desirablecharacteristics.

The composition consists of approximately 45% pigment and 55% vehiclethoroughly and intimately mixed at ordinary atmospheric temperatures bymeans of suitable mechanical mixers. The pigment preferably consists ofasbestos fibre, aluminum silicate, and barium spulphate in the properproportions to produce a troweling consistency when mixed with thevehicle in the above approximate proportions. In making the pigment Ifind the following proportions quite satisfactory:

Parts. Asbestos fibre 28 Aluminum silicate 44 Barium sulphate 28 77Fahrenheit. It should, for best results have a hardness of zero with aneedle penetrometer at the same temperature. y

In the use of petroleum asphalt, I prefer to use av blown product havinga specic gravity at 77 Fahrenheit of from .90 to 1.07 and a fusing point(ball and ring method) of 200 to 250 Fahrenheit. The stearine pitchemployed should, for best re. suits, have a specific gravity of .90 to1.10 at 77 Fahrenheit.

As stated above, I prefer to mix the vehicle andpigment in the ratio of55 to 45, thoroughly and intimately mixed by suitable mechanical mixers,whereby a complete amalgamation of the ingredients at ordinarytemperatures is readily accomplished. The composition of matter thusformed is quick drying and is acid and alkali resistant, being of suchconsistency as to enable its application with a trovvel or brush.

Referring now to the drawing, in Fig. l I'have illustrated the manner ofapplying the composition to a concrete tank or vat l. The composition isapplied in the form of a coating 2 of suitable thickness. The coating isapplied directly to the inner Walls of the concrete vat or inconjunction with a lining of sulphur, which is commonly used in concretepickling vats. After the protective coating has been applied and hasdried sufficiently to form an outer supporting crust, the vat is linedwith planks 3 preferably closely tted by tongue and groove. It is to benoted, in itting the planks in place, that, in the event the crust ofthe coating is punctured, a new crust willv be formed over 'the exposedportion of the compound.

By covering the coating with closely itted boards the coating isprevented from coming into direct contact with the pickling or platingsolution, and is protected from injury or puncture by objects placed inthe vat. It will be noted that the coating preferably extends over theentire inner surface of the vat. Cap plates 4 may be fitted along theupper edges of the vat to hold the side boards in place. v

In Fig. 2 I have illustrated in cross section -a 5 wooden tank having abase 5 and side walls 6. The

coating is applied as inthe case of the concrete tank, to the entireinner surface of the tank and is indicated at 2. In Wooden tanks alreadyis use and which are lined with a coating of lead as is the usualpractice, the protective coating may be applied directly to the leadcoating, or if desired, punctures in the lead lining may be patched withthe protective coating. In either case planks or boards 3 may be fittedover the coating as shown in Fig. 2, the boards being closely ttedpreferably by the tongue and groove method. The boards 3 may be securedin place by strong copper'nails driven through the boards, and coatingand into the tank body. A strip '7 may be applied along the upper edgesof the tank and secured in place by the nails 8.

My invention is not limited in its application to pickling tanks but mayalso be used in connection with water tanks or other containers in whichthereon, and a layer of brous material supported non-acid or non-alkalisolutions are deposited. In such use the planks or boards 3 may beeliminated and the coating exposed to the liquid deposited in thereceptacle.

Although I have not illustrated a steel tank in the drawing, it isobvious that my invention may be suitably applied to such tanks. In thisinstance the protective coating may be thinned and applied with a brush,two or three coatings being sufficient to prevent contact of the steeland pickling solution and corrosion of the steel due to such contact. Ifdesired, the coating so applied may be protected against injury fromobjects moving in the tank, by'a board lining as described in connectionwith Figs. I and 2.

It will be noted that by `my invention I have provided. a protectivecoating composition for tanks, vats and other containers, which iscapable of resisting the attack of acid and alkali solutions, and whichdries quickly upon application, forining a protective and supportingcrust. By my invention the useful life oi tanks, etc. is materiallyincreased and the coating is protected against injury or puncture byobjects rnoving in the tank.

I do not intend to limit myself to the form of rny invention shown ordescribed herein, since various changes may be rnade Without departingfrom the spirit of the invention or the scope of the appended claims.

I claim:

1. A pickling vat having a bottom and side Walls, an acid resistingcoating applied to the inner surfaces of the Vat, said coating havingthe property of forming an outer material supporting crust, the innerportion of the coating being plas- 1m tic, and a layer of fibrousmaterial supported on said crust. n t

2.l A vat comprising bottom and side walls, and a corrosion resistinglayer applied in aplastic condition to the inner surfaces of said Walls,said coating having the property of forming a crust on its outer surfacefor supporting materials thereon.

3. A vat comprising bottom and side walls, and a corrosion resistinglayer applied in a plastic condition to the inner surfaces of saidWalls, said coating having the property of forming a crust on its outersurface for supporting materials on said crust.

4. A container, and a lining of acid and alkali resistant materialintimately applied to the inner surfaces of the container, said materialhaving a hard outer surface and an inner portion in a substantiallyplastic condition.

5. A container, and a lining of acid and alkali resistant materialintimately applied to the inner surfaces of the container, said materialhaving a hard outer surface and an inner portion in a substantiallyplastic condition, and a layer of brous material superimposed on saidlining and comprising a plurality of wooden members closely ttedtogether.

